from a law enforcement standpoint, how do you do it? >> they will hold onto information as long as they can. they will release it when there is nothing more to be done. we have to underline to the public again and again, we should allow professionals to do the work here. the public role is providing information. it is law enforcement job to take the information to analyze it and go forward, not the public's job. bill: even if you're able to identify a person you think needs to be questioned or talked to, not even label ad suspect, you know that guy doesn't look quite right to me, let's go find out who he is, how do you find out he who he is? she will try ainge you late. there is data from the cell phone tower. that is what has been reported. there may be information left at fragments on the scene, pro the pressure cooker, the nylon bag, a fingerprint, face recognition software. they brought in people i heard this morning that work in the federal part on this work with child pornography, used to using facial recognition software to narro